This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A334984 #12 Feb 16 2025 08:34:00 %S A334984 12,16,18,30,32,36,40,42,44,48,50,54,56,60,64,68,70,72,76,78,80,84,90, %T A334984 96,98,100,104,108,110,112,114,120,126,128,130,132,136,140,144,150, %U A334984 152,154,156,160,162,164,168,170,172,176,180,182,186,190,192,196,198,200,204,208 %N A334984 Perimeters of Heronian triangles where the lengths of the middle and largest sides are coprime. %C A334984 This sequence includes the perimeters of all primitive Heronian triangles (A096468). First differs from A096468 at a(16) = 68. %H A334984 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/HeronianTriangle.html">Heronian Triangle</a> %H A334984 Wikipedia, <a href="https://en.wikipedia.org/wiki/Heronian_triangle">Heronian triangle</a> %H A334984 Wikipedia, <a href="https://en.wikipedia.org/wiki/Integer_triangle">Integer Triangle</a> %e A334984 a(1) = 12; there is one Heronian triangle with perimeter 12, which is [3,4,5] and the lengths of the middle and largest sides are coprime (GCD(4,5) = 1). %e A334984 a(5) = 32; there is one Heronian triangle with perimeter 32, [4,13,15] and the lengths of the smallest and middle sides are coprime (GCD(4,13) = 1). %Y A334984 Cf. A051518, A096468, A334983, A334989. %K A334984 nonn %O A334984 1,1 %A A334984 _Wesley Ivan Hurt_, May 18 2020